Patent GB-729441-A (GB)
Title: Manufacture of salts of ª‡-(o-aminoaryloxy)-fatty acids
IPC: C07D265/34
Filed: 1952-02-01
Abstract: Alkali salts of a -(o-amino-aryloxy) fatty acids, which are dyestuffs intermediates, are prepared by reacting an o-alkoxyarylamide of an a -halo fatty acid containing 2 to 5 carbon atoms at a raised temperature with a Friedel-Crafts metal halide condensing agent, preferably in at least a stoichiometric proportion per molecular equivalent of amido reactant, whereby alkyl halide is split off and saponifying the intermediate product or the hydrogen halide free lactam obtained therefrom by treatment with aqueous ammonia, with a caustic alkali to give the salt of the a -(o-amino aryloxy) fatty acid.  These salts are converted to the lactams of the acids on treatment with mineral acids.  The condensing agents may be used in inert solvents, of which many examples are given, or in the molten form, advantageously with additives which lower their melting-points such as alkali metal halides and tertiary bases, e.g. pyridine or trialkylamines; reaction temperatures are generally above 60 DEG  C. Ferric chloride and aluminium chloride and bromide are specified condensing agents.  The amido - starting materials may be obtained by reacting suitable a -halo-fatty acid halides, e.g. chloro- or bromoacetyl chloride, with appropriate o-alkoxy aminoaryl compounds such as the o-alkoxy-amino-benzene, -diphenyl and -naphthalene compounds, the rings of which may be further substituted by such substituents as halogen, alkyl, alkylsulphonyl, alkyl sulphonamido or further alkoxy groups.  In examples: (1) 2-(chloracetylamino)-1-methoxybenzene, obtained by reacting 2-amino-1-methoxy benzene with chloracetyl chloride in chlorbenzene, is added to a heated melt of aluminium chloride and sodium or potassium chloride or triethylamine, whereby methyl chloride and hydrochloric acid are evolved and the product is treated with ice and hydrochloric acid to remove aluminium compounds and saponified to yield the sodium salt of the 2-amino phenyl ether of glycollic acid which is converted into the lactam by means of dilute hydrochloric acid; (2) 4-methyl-2-amino-1-methoxy benzene and 5-nitro-2-amino-1-methoxy benzene are chloracetylated and the products treated as above yielding the sodium salts of the 4-methyl-2-aminophenyl ether and 5 - nitro - 2 - aminophenyl ether respectively of glycollic acid and the corresponding lactams; (3) 4 - chloro - 2 - amino - 1 - methoxy benzene is similarly treated yielding the sodium salt of 4-chloro-2-amino phenyl ether of glycollic acid and the lactam; (4) 4-sulphamido-2-amino-1-methoxybenzene is chloracetylated, reacted with an aluminium halide melt and the product purified as in (1); the product, of composition C8H9N2O4SCl, is either neutralized in aqueous solution with ammonia and the resulting lactam of 4-sulphamido-2-aminophenyl ether of glycollic saponified with caustic soda, or directly saponified to the sodium salt of the acid; (5) 1 : 4-dimethoxy-2-aminobenzene is treated as in (4) yielding the intermediate product C8H8NO3Cl and the lactam and sodium salt of 4-hydroxy-2-aminophenyl ether of glycollic acid; (6) 4 : 41 - diamino - 3 : 31 - dimethoxy-diphenyl is converted to the 4 : 41-dichloracetylamino compound which is reacted generally as in (1), the intermediate being saponified to yield the potassium salt of 4 : 41-diamino diphenyl-3 : 31-bis-oxyacetic acid from which the corresponding di-lactam is obtained; (7) as in (6) using, however, 4 : 41 - di - (bromacetylamino) - 3 : 31-diethoxy diphenyl to yield the same products; (8) 4 - oxalylamino - 41 - amino - 3 : 31-dimethoxydiphenyl is chloracetylated and the product reacted as in (1) yielding the sodium salt of 4 : 41-diamino-3-hydroxy diphenyl ether of glycollic acid which yields the chlorohydrate of the corresponding lactam on treatment with concentrated hydrochloric acid; (9) 4 : 41-diamino - 3 : 31 - dimethoxydiphenyl is diacylated with a -bromo-butyryl chloride which is reacted as in (6) yielding an intermediate compound C20H23N2O5Br and the di-potassium salt of 4 : 41-diaminodiphenyl-3 : 31-bis-(a  : a 1-diethyl) oxyacetic acid; if a -bromo-propionic acid bromide is used as acylating agent, the di-salt of 4 : 41-diaminodiphenyl-3 : 31-bis-(a  : a 1-dimethyl) oxyacetic acid is formed; (10) 1-amino - 2 - methoxy naphthalene is chloracetylated and the product reacted generally as in (1) yielding the sodium salt and lactam of 1 - amino - 2 - naphthyl oxyacetic acid; (11) 1 - amino-2-ethoxy naphthalene is reacted as in (10).